Autonomous or semi-autonomous movement of mechanisms and machines is increasingly desirable for many operations including those related to mining, earthmoving and other industrial activities. Autonomously operated machines may remain consistently productive without regard to a human operator or environmental conditions. In addition, autonomous systems may permit operation in environments that are unsuitable or undesirable for a human operator. Autonomous or semi-autonomous systems may also compensate for inexperienced human operators as well as inefficiencies associated with repetitive tasks.
Maps with designated paths and boundaries may be set for such autonomously and semi-autonomously operated machines. At a site in which a machine may operate in proximity to a crest such as a ridge, embankment, high wall or other change in elevation or sloped area, remaining within the designated boundaries becomes especially critical. Systems that typically monitor and control autonomously or semi-autonomously operated machines may include global positioning systems or systems that determine position based upon the revolutions of the tires or other driven components of the machine. While such systems are capable of determining the position of a machine relative to a map, they do not account for changes that occur to the terrain after the map has been developed.
Automated systems for detecting a change in terrain may be used to determine whether a machine is approaching or adjacent a crest. Calibration of such change in terrain systems often require a balance between a system that is too sensitive, which may result in the generation of false positive responses, and a system that may allow a machine to move closer to the crest than is desirable.
U.S. Pat. No. 7,881,497 discloses a system for controlling an autonomous vehicle through a vision based navigation and guidance system. The system uses a camera to detect images and applies such images to an edge detection circuit. The edge detection information is used with navigation information that may be provided from various types of systems including inertial movement, global positioning, stereo vision, radar, mapping and the like.
The foregoing background discussion is intended solely to aid the reader. It is not intended to limit the innovations described herein, nor to limit or expand the prior art discussed. Thus, the foregoing discussion should not be taken to indicate that any particular element of a prior system is unsuitable for use with the innovations described herein, nor is it intended to indicate that any element is essential in implementing the innovations described herein. The implementations and application of the innovations described herein are defined by the appended claims.